Transmission cooling-can it be improved?

[Mr Big]

Struggling to make sense of that, not sure what reprogramming would do to change that? I do have a recall that needs to be done so maybe I will talk to them when I take it in and see if there are any updates that need to be done. What was the reason you have the pcm/tcm updated?

Recall and Technical Service Bulletin. I was not expecting anything to change except the false Catalytic Converter error codes. So, I assumed that maybe the PCM software update changed something to do with temps. I really don't know, but it was a nice surprise.

 

[Bmac1955]

Read any info on the 10r80. I read that heat is the downfall along with CDF drum for these Trans. It is no wonder Ford redesigned the Stat. My guess. My 2019 is in dealership with 46k. Want them to replace the stat do to seeing high temps of 218 to 224. Highway driving doing 65 with outside temps of 70. Doesn't seem right to me. Will see. I do have Ford Protect warranty.

 

[Calidad]

My 2019 around 65,000 showed early signs of the Tstat issue but at that time I didn’t know about it. 820 miles over three passes in July heat pulling a permitted over sized boat thats around 8700lbs all up.

The early signs of the Tstat was slow to cool and not cooling off lower than 210 on the transmission. The engine temp doesn’t display till 228.

The transmission fan kicks on at 212 and is also on when AC runs. During that trip we ran front and back heaters full blast during climbs over the passes one was in 100 degree weather. RPM in the 2000-2300 range definitely kept heat down vs 2500+rpm. 230 is getting hot. 240 is hot and time to pull off or be heading down hill. I did pull off on our longest climb 2nd morning cooler outside temps and thats when I noticed we couldn’t get it to cool past 210 (note later after the Tstat replacement it cools down fast and lower than 210!)

Flat towing at 55-60 pre tstat replacement early on in the failure… Flat 90+ temps 212-225 with AC on was the range. Near the end of the 820 mile haul the Tstat issue was getting worse (again I didn’t know but could see the worse cooling issues developing)

Last 19 miles of that trip was over a 7400ft pass. At 5800 ft the cooling even after pulling off for 30 minutes was not dropping like it should and the heat spike was happening quicker I was pulling off at 230 because we had a long climb still. Called a tow guy to drag the boat the last 19 miles over the pass. That was July 1 2024. No more towing till October and that was from 6000 up to 7400 then down to sea level cooler temps fresh synthetic Penzoil Temps were cool ish 200-220 for 180 miles same boat. Then in December I was solo heading to the cabin at 70mph and got a engine temp spike and transmission 234 temp spike!! Bingo!!! I knew it was the Tstat!!!! Around town transmission was running 212-215 at that point. Updated the Tstat immediately 180-190 around town. Solo to the cabin 180-190.

Pulling the boat 25 miles mid day through stop and go traffic hell 215 then climbing up a decent grade finally out of traffic it cooled down!!! On the climb to 201!! At that point I knew that stupid Tstat issue was definitely my problem.. This years haul over the 7400ft pass I got to use a buddy’s 2024 F250 6.8L gasser 6spd AT. I watched the trans temps and it has a factory air to trans fluid cooler you can hear that fan kick on btw. 55 mph it ran at 190-200. Heavy climbs it actually cooled down because the fan kicked on 210 after traffic stop up a steep grind at 40mph and 3700rpm (different power band than the 3.5) it immediately cooled to 200 in about 4 minutes! The 6.8 doesn’t match the 3.5 pulling power till your in the 3500-4000rpm range!! Under 3500rpm you will not achieve highway speeds if 50-55mph. Vs the 3.5 at 2500-3000rpm the Expedition easily hauls my boat to speed getting on the highway hill or no hill. Very different experience regarding power between those two engines.

I do think an air to transmission cooler would be a huge deal for those of us dragging 7000+ lbs especially draggy trailers like boxy RVs and big draggy boats. Its definitely in my list of curiosity for possible modifications.

I want to eye ball my buddies F250 closer to see how Ford rigged the air to transmission cooler. I don’t think the F150 is setup that way (maybe the heavy payload F150 package? But those are pretty rare)

As for towing? This setup tows really nice with empty fuel tanks. Trailer is electric hydraulic 4 disc brakes huge discs! It stops well but not quickly. The F250 by the way didn’t stop it any quicker! The brake gain is different between the Ex and 250! The Ex I ran brake gain at the highest level. The F250 I ran it at 8. They were comparable in stopping between the two.

The Expedition engine braking was definitely effective and very important crossing three serious mountain passes over 5000ft. I even followed a semi down one of the more challenging passes that didn’t have any tail lights and seemed to be very conservative on engine breaking happy to just follow him I rarely used any brakes and when I did it was just to shed 5-10 mph with a short hard brake application then off to let brakes stay cool. When we hit the bottom the semi pulled off- I’m convinced he had zero trailer brakes and nursed that thing down the mountain all gearing given we got passed by semi’s absolutely hauling ass!!! Definitely not my thing!! 40-45mph on the long down hill steeps was perfectly comfortable for me!!!

 

[duneslider]

I have been watching closer and last night we did some mountain biking and did a little shuttling. With the bike rack and 7 bikes and 8 adults in the Exp and climbing the canyon I saw transmission temps of 219. Air was cool (65 degrees) but it was steep and elevation at the top was close to 9000'.

Just a note, this is with the updated thermostat that I just installed a couple weeks ago which in my opinion didn't seem to make any difference in the temps.

I have a long drive this week. 600 miles each way, no trailer, but 4 adults and bike rack with 4 bikes. Salt Lake to Sunrise AZ. I will keep an eye on temps as we cruise through the desert. I am suspecting transmission temp will hover around 214. Basically, what I am coming to fully believe is that the method ford is using to "cool" the transmission is not adequate and adding an air to oil cooler will drastically improve things.

I did find a high flow thermostate controlled transmission cooler valve that is set at 185. So, that could be an option to swap to the air to oil cooler but still allow for the oil to maintain a temp of 185deg...